Power-efficient operation and maximization of performance are two important issues in the design of modern electronic devices. For example, wireless devices often are powered by a battery or other internal power source. However, when a user has to charge or change the battery too often, the device becomes less useful, and therefore power-efficient operation of such a device is important for enhancing the user's experience of the device.
For a device that can be plugged into, and operated with line power, power-efficiency is less critical. However, with the increasing prevalence of wireless devices (e.g., Bluetooth devices), the time associated with recharging batteries of the wireless device and the time of not having the device available when it is needed becomes a hurdle that can limit the practical utility of the devices.